Apparatus for manufacturing steel.



EENJAMIN.

APPARATUS FOR MANUFACTURING STEEL.

APPLICATION FILED NQY, 7, I918.

PatentedJuly '7, 191i 2 MEETS-SHEET 1.

1 0' a; am Z. i? J.

G. H. BENJAMIN.

APPARATUS FOR MANUFACTURING STEEL APPLICATION FILED NOV. 7, 1913.

1,102,382, Patented July 7, 1914.

Icing.

snare-n snares PnEPENT OFFICE.

I GEQRQE HILLAEE BEZEIJAMIN, OF NEW YORK, N. "Y.

APTEARAE'US FOR MANUFACTURING STEEL.

I Specification. ofLetters Patent.

@rlglnal application filed January 4, 19 13, SerialNo. 740,103. Dividedand this application filed November 7,1913. Seria11Io.799,ZQ3.

To call whom.- it may concern.

Be it known that I, GEoRGE HILLARD BEN- JAMIN, a citizen of the UnitedStates, residing' at New York cit in the county and State f New York,ave invented certain new and useful Improvements in Apparatus forManufacturing Steel, of which the following is a specification.

My invention relates particularly to the treatment of molten steel byhigh temperature, such asmay be obtained in an electric furnace,together with suitable introduced bodies for the removal of phosphorusand other bodies from the steel.

' In a prior Patent N 0. 1,051,065 granted to me, dated January 21st,1913, I have de scribed a method of treating steel for the removal ofphosphorus, etc, and. which method involved-the introduction of variousbodies which will combine with phosphorus and other bodies at the hightemperature of an electric arc, after which, purified metal was run intoa second furnace, also heated by 'e'lectricity, and there combined withthe necessary amount of carbon or other bodies which it was desired tointroduce into the steel. This method further involved the continuousheating by electricity.

My present method differs therefrom in that heating is first eiiected byregenerated gas and air and subsequently by electricity for only suchtime as is necessary to bring about the chemicalcombinations between theintroduced bodies and the bOdies carried by the steel, which cannot beeffected by the gas and air heating.

I am aware that it has been proposed to carry out the above statedprocess in a single furnace, but experience has demonstrated that it ispractically impossible to thus eliminate the necessary amount ofphosphorus and other materials, and that this is due to the fact thatsteel cannot be completely 'slaggod in a single furnace. To

overcome the dilficulties above set forth, I

proceed in the manner which I will now describe, and make use oi?apparatus such as is illustrated in the accompanying drawings.

. and described. in the specification.

This application is filed as a division of my application Serial No.540,103 filed January 4th, 1913, which application relates specificallyto an improvement in the art of manufacturing steeldescribed, thepresent application being limited to the apparatus Referring to thedrawings; Figure 1 represents a plan view of an arrangement of furnacesa, apted to carry my invention into efifect. Fig. 2 is a verticalsection of an electrlc furnace, a side and vertical section of a gasfurnace, and a side elevation of the hood of a gas furnace as removedfrom the hearth, taken on the line IIII of Fig. 1 looking from the left.Fig. 3 is a vertical section of a gas furnace, a. side elevation of thehearth detached from the roof, a side elevation of a gas furnace, andside elevation of a mixer, taken on the line IIIIII of Fig. 1.

Itwill be understood from reference to the figures, that they are in asense diagrammatic and intended not only to show the generalconstruction of the furnaces, but the relation of the furnaces to eachother, and also the relation of the movable hearths to the fixed roofs.

Referring to the drawings: 5 represents a mixer of the usualconstruction, mounted on a track 6 and provided with means 7 consistingof a cylinder and piston operated by a motive fluid for tilting themixer.

8 and 9 represent two circular trackways which overlap. Mounted incarriages 10 on these trackways, are a series of movable hearths 11.Means 12 are provided for tilting the hearths, consisting of a cylinderand piston operated by a motive fluid.

Located at equidistant points on the trackways 8 and 9, are a series offixed hoods 13 and 14. The hoods 13 are heated by regenerated gas andair introduced through the medium of the burners 15, and the hoods 14through the medium of the adjustable electrodes 16. The hoods 18 and 14occupy a fixed relation to the trackways, but are adjustable vertically,by means 17, consisting of a cylinder and piston operated by a motivefluid. Regenerated. gas and air is-introduced to the burners 15 throughthe pipes 18 able valves for controlling the gas and air. Asthearrangement of the pipes for gas an." ail and the controlling valves maybe altered, n0 specific description is thought necessary. of those shownin the drawings.

20 represents a ladle for receiving. the molten steel in a finishedcondition, and 21 slag troughs.

-My improved Patented July 7, 1914..

19, which are supplied with suitmethod and the operation Iillustrated-asopen, that 15, the 'hearths in .I-eiqmsed to theatmosphere. Manifestly the .irachway. Further, the hearths, while in ofthe structure shown and described, may I be effected as follows:Bessemerized iron,

from which silicon, carbon-and phosphorus has been partially removed ina converter (not shown) is discharged into the mixer 5, and from themixer 5 (shown at the right hand side Fig. into one of the movablehearths 11, which at the time is-under one of the gas hoods 13 (shown atthe right hand side of Fig. 2), the purpose of which is to keep themetal hot. If desired, at this time an oxidizing basic flux may becharged upon the metal on the hearth. As soon as the hearth is filled,the hood 13 is raised (as shown at the right of Fig. and the hearthmoved along trackway 9" to the position of the gas hood 13 at the lightof the mixer. Here it is held for a time under the influence of the heatin the gas hood, when further flux may be introduced. The slag is thenwithdrawn and the hearth moved under the electric hood 14c, and lime orlime and. carbon introduced, which, 1 .er the influence of the electricheat, will. combine with the phosphorus, etc., in the steel, after whichit is again cleaned of slag, and the hearth moved forward to the left infront of the discharging position, 2'. e., in front of the positionwhere the ladle 20 is located as shown at 21 at the top of Fig.1. Atthis position further carbon may be introduced. It will be understoodthat as the. first mentioned hearth (designated by the letter A) ismoved from the mixing position, a previously emptied hearth (designatedby the letter B) is moved'into the position formerly occupied by A,along the trackway 8 to be filled, and then moved progressively alongthe trackway 8 under the successive hearths to the dischargingposition.

It will be observed from the description, that in. moving from thefilling position to the second position (designated by the letter S atthe right .and left) the temperature is such as may be maintained by gasand air with the consequent known reactions, as usual in a basic openhearth furnace, and that when moved to the third position (designated bythe letter T at the right and, left) the temperatureis such as to effectall the reactions usual in an electric furnace, and when moved to the.discharging position (designated-bythe letter D) the temperature issuchas to m'ai-ntain the metalsufiicientlyfi'uid to pour.

I In Fig. 1 of the'drawing, the trackway is;

moving from one'position to the' next, are

trackway may be inclosed (as indicated in dotted lines on the upperright hand corner. of Fig. 1) so as to prevent the escape'of heat,- and.further, any mechanical "means may be employed to move the hearths uponthe definite positions or at any part of the trackway, may be cleaned ofslag, the removal of the hearths from the hoods allowing unusualfacilities for removing the slag,

It will be understood from the description as far as given, that thesteps involving the carrying out of the above process are as follows:First: Pouring the metal on to a 'hearth'ythen fluxing and subjecting tothetemperature such as may be .obtained from the regenerated gas andair; then moving the hearth to the second position and again subjectingit to the temperature of regenerated gas and air and again filming; thenmoving the highly heated cleaned or slagged metal into the thirdposition, introducing lime, and there subjecting it to the hightemperature and other effects of transmitted electric current to producefinal separation of the phosphorus, carbon and other -sepa-' rablematerials; then again removing slag and finally moving to thedischarging position, there introducing carbon and finally discharginginto a ladle or other device.

It will be understood by those skilled in the art to which thisinvention belongs, that the hearths may have an acid or basic lining,

depending upon the treatment to which the material is to subjected.Further, that fluxing may be accomplished with all known fluxes. Furtherthat the temperature effects of the electric current may be obtainedeither by means of electrodes dipping. into the fused material on thehearth thereby heating by resistance; or partially dipping into thematerial and thereby heating partially by an arc and partially byresistance; or that in place of electrodes, heating might beaccomplished by induction, it being wi hin the in tent of the inventionto use any method of electric heating which will produce the necessarychemical reactions when the hearths are in the third position.

It will be further understood that the major portion of the heatnecessary to produce the requisite reactions is created by thecombustion of gas and air and that only a small amount of electricalenergy is necessary to raise the temperature of the metal on the hearthswhen under the electric hoods, to that wherein chemical actions may takeplace which are not possibleunder the temperatures produced by as andair, thus effecting a great saving in the cost of the electrical energyand chcapening the process.

Further,'that owing to the disposition of the hearths as shown in thedrawings, rapidity of action and facility of manufacturing is acquiredover known methods Where at- Y tempts have been made to produce theneces-' sary successive reactions, first by fluence of heat through gasand air, and then by electricity in the same furnace. Further,

. that by reason of the system of] movable hearths and fixed-hoods, theWeari'and tear the in- I 1,102,3sa 1 a for heating certain other of saidhoods and hearths to the temperature due to the passage of an electriccurrent through the material on the hearths,

2. In an apparatus of the class described, the combination of a mixer,two trackways, a series of movable hearths, a series of hoods occupyingfixed positions on said trackways, means for vertically moving saidhoods, means for heating certain of said hoods and hearths to thetemperature due to the combustion of gas and air, and means for heat ingcertain other of said hoods and hearths to the temperature due to thepassage of an electric current through the material on the hearths.

3. In an apparatus of the class described, thecombination of a mixer,two trackways, a series of movable hearths, a series of hoods occupyingfixed positions on said trackways, means for vertically moving saidhoods, means for heating certain of said hoods and hearths to thetemperature due to the combustion of gas and air, means for heatingcertain other,of said hoods and hearths to the temperatiire due to thepassage of an electric current," means for tilting said hearthstodischarge their contents of slag or metal, and mcans'ior receiving therefined metal. I

4. In an apparatus of the class described, the combination of a mixer,two circular trackways, a series of movable hearths, a series of hoodsoccupying fixed. positions on said trackways, means for verticallymoving said hoods, means for heating certain of said hoods and hearths.to the temperature due to the combustion of gas and air, means forheating certain other of said hoods and hearths to the-tcmperaturedue tothe passage of an electric current through the material on saidihearths,means for tilting said hearths to discharge their contents of slag ormetal, and a ladle for receiving the refined metal. 1

' 5. In an apparatus of the class described,

the combination of a mixer, two circular trackways, a covering for sandtra'ckways,'a

series of movablehearths, a series of hoods occupying fixed positions onsaid trackways, means for vertically moving said hoods, means forheating certain of said hoods and hearths to the temperature due to thecombustion of gas and air, means for heating certain other of said hoodsand hearths to the temperature. due to the passage of an electriccurrent through the material on said hearths, means for tilting saidhearths to discharge their contents of slag or metal, and a ladle forreceivingthe refined metal.

6. In an apparatus of the class described, the combination of a mixer,two circular trackways, a series of hearths mounted on wheeled carriagesand adapted to be moved over said trackways, a series of hoods occupyingfixed positionson and over said track- Ways, means for vertically movingsaid hoods, means for heating certain of said hoods and hearths to thetemperature due heating certain other of said hoods and hearths to thetemperature due to the pas- 80. to the combustion of gas and air, meansfor sage of an electric current through the ma" terial on the hearths,means for tilting said hearths to discharge their contents of slag ormetal and a ladle for receiving the re; fined metal. A

7. In an apparatus of the class described, the combination of a mixer,two circular overlapping trackways, a series of hearths adapted to bemoved over said trackways, a series of hoods occupying fixed positionson and over said trackways, means for verticallymoving said hoods, meansfor heating certain of said. hoods and hearths to the.-

temperature due to the combustion of gas andair, means for heatingcertain other of said hoods and hearths to the temperature due to thepassage of an electric current through'the material on the hearths,means for tilting said hearths to discharge their contents of slag ormetal, and a ladle for receiving the refined metal.

8. Inan apparatus of the class described,

the combination of a mixer, two trackways,

a series of movable hearths, a series ofhoods occupying fixed positionson said trackways, means for vertically moving said hoods, gas and airpipes connected to certain of said hoods, electrodes connected tocertain other of said hoods, means for tilting said hearths to dischargetheir contents of slag or metal, and a. ladle for receiving the refinedmetal.

In testimony whereof, I afiix my signature, in presence of twowitnesses.

GEORGE HILLARD BENJAMIN. Witnesses: v HELEN E..KOELSCH, CONSTANCE-H.HANSSON.

